Is this poem good?

Hey guys! My brother's teacher entered him in a poetry contest, and asked me if it was good. The poem was brilliant. Well, he's a fourth grader, so I am clearly astonished. Tell me your comments about this poem, and please be as descriptive as possible, i really want to edit his poem, if it isn't a violation in the contest's rules! :)
In a frigid, unfriendly afternoon,
Rain cascades down my window pane.
The dawning radiance of the sun struggles,
As mischievous clouds roguishly cover the heavens.
Wretchedness takes over my bare soul,
As I wonder, when will this sorrow come to an end.
With perseverance, I reach toward my gold trimmed mahogany desk.
I seek sympathy from the harsh spirits beneath these drawers.
I draw out my closest companion, a pencil,
The strongest blacksmith, a sharpener,
And a piece of paper, the birth place of all.
As lead engraves my every thoughts and darkest feelings onto this piece of paper,
A sprout of happiness darts my heart.
I write and write, numerously sharpening my pencil.
Silencing the world around me, I ferociously scribble on this piece of paper.
Concentrating, I travel deep in my mind details that lurk behind these walls,
And before long, bales of paper are now filled with passion instead of empty lines.
An intense sun emerges from the clouds,
Showering my murky, bitter room with warmth and sunlight,
My sorrows and griefs have been splattered with new hope of overcoming a new day.
My darkest thoughts are vanquished,
And the shadows of misery fade over my shoulders.
The bars that have imprisoned me have collapsed into heaps of ashes,
And my soul rejuvenates from the clutches of darkness.
These tools have helped me overcome my dread,
As i feel free and happier than ever.
This is what makes me feel happy.

This is a wondeful poem. I am an English teacher in the UK - I teach 11-16 year olds and I wish my pupils could write poems like this! It creates a fantastic evocative atmosphere and he shows a wide range of vocabulary. He is very talented!

Yes, I also hope he succeeds. He is still going to have to compete against the age groups of 10-16. Its against the rules for any help, so I am definitely excluded from all of this. Thanks for the comments, and overall, i think he's going to win.

Not bad. Noticed a few errors that I hope the teacher caught before she/he entered it, but nice nevertheless. Don't get any hopes up. Those poetry contests are a scam, yes even the ones teachers put their students poetry/prose in. Sorry.
I would consider it prose, not poetry but that's subjective. Tell your brother to keep writing and improving. He's got some talent that needs work.

Yes, he does have some talent. Its not hard to believe he got his traits from me :)
Thanks for the comment. Really appreciate it, and I'm not sure it is a scam. Its a $50 cash prize for first place and i get a share he he!